Error: Either zero or 2 or more [DropdownMenuItem]s were detected with the same value I/flutter (18363): ‘package:flutter/src/material/dropdown.dart’:

I had the exact same error, multiple Dropdowns all feeding from the same static list, the only difference is that in my case, it was a list of Objects, not Strings.

So, if it’s a static list, there’s no way it’s empty, no duplicate values in the list, AND you already make sure value is not empty? Then the only option remaining is that item.value is different than value

In my case, as it was an Object list, I had to overwrite operator == and hashcode methods in my Object class.

bool operator ==(dynamic other) =>
      other != null && other is TimeSelection && this.hour == other.hour;

  @override
  int get hashCode => super.hashCode;

And that was it. I didn’t had to initialize _value1 or _value2